Films for printing

ABSTRACT

Printing layers and films for printing are disclosed. Methods for preparing such films also are disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 61/921,641 filed Dec. 30, 2013, which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

Films may be used for printing materials, such as signs and banners.Inkjet printers may be used to print upon such materials using solvent,eco-solvent, mild solvent, latex, and/or ultraviolet (“UV”) inks. Thepresent invention includes films for printing and methods of theirmanufacture.

SUMMARY OF THE INVENTION

In one embodiment, the invention includes a printing layer of a filmcomprising a blend of at least one high absorption capacity material andat least one low absorption capacity material.

In another embodiment, a film for printing. The film includes a printlayer, a core layer, and an adhesive layer, and the core layer isbetween the print layer and the adhesive layer. In addition, theprinting layer includes a blend of at least one high absorption capacitymaterial and at least one low absorption capacity material.

The following description illustrates one or more embodiments of theinvention and serves to explain the principles and exemplary embodimentof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary embodiment of a film of the presentinvention;

FIG. 2 depicts an additional exemplary embodiment of a film of thepresent invention;

FIG. 3 depicts an additional exemplary embodiment of a film of thepresent invention;

FIG. 4A is an electron scanning microscope image of a printing layerembodiment;

FIG. 4B is an electron scanning microscope image of an additionalprinting layer embodiment;

FIG. 4C is a DMA profile for the printing layers of FIG. 4A and FIG. 4C;and

FIG. 5 is an electron scanning microscope image of an additionalprinting layer embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of thepresent invention, one or more examples of which are illustrated in theaccompanying drawings. Each example is provided by way of explanation ofthe invention and not by limitation of the invention. It will beapparent to those skilled in the art that modifications and variationscan be made in the present invention without departing from the scope orspirit thereof. For instance, features illustrated or described as partof one embodiment may be used on another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents. In addition, the use of referencecharacters with the same two ending digits as other reference charactersto indicate structure in the present specification and drawings, withouta specific discussion of such structure, is intended to represent thesame or analogous structure in different embodiments. Unless otherwiseindicated herein, all percentages used for a component refer to thepercentage by weight.

In some embodiments, the present invention includes films and othermaterials for printing or marking with ink. In some embodiments,materials of the present invention may include a print layer (alsointerchangeably referenced as a printing layer herein), an optional tielayer, a core layer, and an adhesive layer. In other embodiments, suchmaterials may exclude certain layers. In some embodiments, the totalfilm thickness may be from about 2.5 mils to about 3.2 mils.

Print layers of the present invention may include a blend of at leastone high absorption capacity material, such as poly(methyl methacrylate)(“PMMA”), polystyrene, polyethylene terephthalate glycol-modified(PETG), and styrene-based copolymers, impact modified polystyrene,styrene acrylic copolymer, styrene-olefin copolymer,styrene-acrylic-olefin copolymer, acrylonitrile butadinene styrenepolymer, styrene acrylonitrile polymer, and copolyester polymer, and atleast one low absorption capacity material, such as an olefin polymer,including random copolymers and/or block copolymers. By way of example,suitable olefin copolymers may include, without limitation, ethyleneacrylate coplomers, such as ethylene acrylic acid (EAA), ethylene methylacrylate (EMA), and ethylene butyl acrylate (EBA), ethylene vinylacetate (EVA), and/or ethylene acrylic ester terpolymer. As used herein,unless the context dictates otherwise, the term copolymers may alsoreference terpolymers. In one particular embodiment of the presentinvention, the print layer includes PMMA and an olefin polymer,including random copolymers and/or block copolymers.

Any suitable formulation may be used. In some embodiments, at least 10%low absorption capacity material may be present in the formulation. Inother embodiments, at least 17% low absorption capacity material may bepresent in the formulation. In addition, in some embodiments at least20% high absorption capacity material may be present in the formulation.In some embodiments, about 20% to about 83% high absorption capacitymaterial may be present. In still some embodiments, less than 83% highabsorption capacity material may be present. Notably, neither PMMA norolefin copolymers were observed during testing to independently providesuitable materials for ink printing.

A print layer may have any thickness suitable for a particularembodiment. In some embodiments, a print layer may have a thicknessgreater than about 0.38 mils. In some embodiments, a print layer mayhave a thickness in the range of about 0.6 mils to about 1.0 mils,including each intermittent value therein. In other embodiments, a printlayer may have a thickness in the range of about 0.6 mils to about 3.0mils. In still other embodiments, a print layer may have thickness up toabout 6.0 mils. Any remaining layers of the film may be of any suitablethickness for a particular embodiment.

In some embodiments, the print layer may include multiple adjacentlayers. For example, in some embodiments, a print layer may include twoadjacent layers, wherein each layer includes the same blend of at leastone high absorption capacity material and at least one low absorptioncapacity material. In addition, in some embodiments at least one layerof the two adjacent layers further includes absorbing particles, such assilica, alumina silicate, nano clay, calcium carbonate, zinc oxide,titanium dioxide, and/or other absorbing particles or other suitableabsorbing particles or resins. In some embodiments, the particle sizesmay be in the range of about 0.1 to about 10 microns, including eachintermittent value therein. In addition, multiple particle sizes may bepresent in some embodiments. For example, various particle sizes may bepresent in a single print layer in some embodiments. In addition,embodiments having multiple print layers may each have either the sameor distinct particle sizes.

By way of example, FIG. 1 depicts an embodiment of print layer 100having layer 102, which includes at least one high absorption capacitymaterial and at least one low absorption capacity material, and layer102′, which includes the same composition as layer 102 but furtherincludes absorbing particles. Although not shown, adhesive, such as apressure sensitive adhesive, may be disposed upon an outer face of thefilm and a release liner (not shown) may optionally be in contact withthe adhesive such that the adhesive is between the release liner and theouter face of the film. In some embodiments, the film comprises aremovable release liner and a pressure sensitive adhesive, wherein thepressure sensitive adhesive is disposed upon the adhesive layer and therelease liner is adjacent to the pressure sensitive adhesive, such thatthe pressure sensitive adhesive is disposed between the adhesive layerand the release liner.

In some other embodiments, additional layers having either the same ordifferent compositions may be included in a multilayer print layer. Instill other embodiments, a film of the present invention may be a singlelayer consisting of only the printing layer. In such embodiments, anadhesive, such as a pressure sensitive adhesive, may be applied directlyupon that layer. Each layer of a multilayer print layer may be of thesame thickness or may have varying thicknesses.

In some embodiments of the present invention, a multilayer print layermay have a morphological gradient. In such embodiments, a print layermay include a first layer in which PMMA is the major component of theblend in the layer and a second layer having the same blend componentsas the first layer but in which PMMA is the minor component. This maycreate different absorption capacity between the two adjacent layersforming the image receptive layer. The print layer may include at leastone layer comprising at least 50% by weight PMMA and at least one layercomprising less than 50% by weight PMMA.

The print layer may be formulated to include an ultraviolet stabilizerpackage in some embodiments, particularly when the materials areintended to be used for outdoor display. In some embodiments, a suitableultraviolet stabilizer may include the ultraviolet light stabilizerAmpacet UV 10561, available from Ampacet Corporation. By way of furtherexample, the ultraviolet stabilizer package may include free radicalscavengers and an ultraviolet light stabilizer. Free radical scavengers,such as hindered amine light stabilizer (HALS), may be present, alone orin addition to UV light stabilizers, in an amount of about 0.05 to abouttwo weight percent per layer, and the UV light stabilizers, such asbenzophenone, can be present in amounts ranging from 0.1 to about 5weight percent per layer. Such ultraviolet stabilizer packages may beincluded in the print layer. In multilayer print layers, suchultraviolet packages may be included in some or all of the layers of theprint layer.

Similarly, print layers of the present invention may also oralternatively include heat stabilizers. Heat stabilizers may includeFerro 1237, Ferro 1720, and Synpron 1163, all available from FerroCorporation Polymer Additives Division, and Mark V 1923, available fromWitco Corp. By way of example, heat stabilizers may be present in anamount from about 0.2 to about 0.15 percent by total weight of a printlayer, including each intermittent value therein. In multilayer printlayers, such heat stabilizers may be included in some or all of thelayers of the print layer.

In some embodiments, a print layer may also include a compatibilizer. Byway of example, a suitable compatibilizer may include a block copolymer.In some particular embodiments, styrene-ethylene-butylene-styrene may beincluded as a compatibilizer in a print layer, such as in a print layerhaving a blend of PMMA and ethylene copolymer. A compatibilizer also mayimprove the gloss of the print layer in some embodiments. In multilayerprint layers, such compatibilizers may be included in some or all of thelayers of the print layer.

Some embodiments of print layers of the present invention may alsoinclude one or more process aids, such as Ampacet 10919, which isavailable from Ampacet Corporation. In addition, some print layerembodiments may include a flame retardant compound. By way of example,some embodiments may include FR-2005 (which is a flame retardant andultraviolet stabilizer and available from Polyfil Corporation). In otherembodiments, the print layer may also include one or more pigments,antiblock agents, and/or matting agents.

As indicated, materials of the present invention may also include a tielayer. When present, a tie layer may be located between a print layerand a core layer of the film. A tie layer may be comprised of anysuitable material for a particular embodiment. In some embodiments, atie layer may improve the interlayer adhesion between the print layerand the core layer. In some embodiments, a tie layer may be included ifthe blend of the print layer includes more than 50% by weight of PMMA.

Suitable tie layer resins may include, by way of example, ethylene vinylacetate, such as those sold by Celanese under the Ateva trade name,Elvax resins sold by ExxonMobil, Bynel resins sold by DupontCorporation, and Evatane resins sold by Arkema. In addition, otherresins suitable for a tie layer may include random terpolymer ofethylene, vinyl acetate and maleic anhydride, such as OREVAC-T9304 soldby Arkema, and materials of similar structure.

Embodiments of the present invention may also include a core layer. Suchcore layers may be comprised of any material to provide suitablemechanical strength and a desired opacity to the film. In someembodiments, any suitable olefin polymer or combination of olefinpolymers may be included in the core layer. By way of example, a corelayer may be comprised of any suitable olefin polymer. In someembodiments, a core layer may comprise polyethylene, such as low densitypolyethylene and/or linear low density polyethylene may be present inthe core layer. In other embodiments medium density and/or high densitypolyethylene may be present in the core layer. In addition, the corelayer may optionally include color pigments.

In some embodiments, the present invention may also include an adhesivelayer. The adhesive layer may include ethylene vinyl acetate. In someembodiments, the adhesive layer may also include polyethylene, such aslow density polyethylene and/or linear low density polyethylene. Anadhesive layer may also have one or more ultraviolet stabilizers,process aids, and/or flame retardants. A suitable adhesive may beapplied to the adhesive layer, optionally with a release liner, in someembodiments.

FIG. 2 provides an exemplary embodiment of a film of the presentinvention. As shown, FIG. 2 depicts a film 200 having a print layer 202,a tie layer 204, a core layer 206, and an adhesive layer 208. The layersof this example may have the compositions as described above.

FIG. 3 provides another exemplary embodiment of a film of the presentinvention. As shown, FIG. 3 depicts a film 300 having a multilayer printlayer including layer 302 and layer 302′, a tie layer 304, a core layer306, and an adhesive layer 308. The layers of this example may have thecompositions as described above. In this embodiment, the multilayerprint layer may optionally create a morphological gradient.

In some embodiments, as indicated above, films of the present inventionmay also include a pressure sensitive adhesive layer and a releasableliner. The adhesive may be applied upon any suitable layer of the film,such as, for example, an adhesive layer. In single layer embodiments,the adhesive may be applied directly upon that single layer. The releaseliner may be position adjacent the adhesive such that the adhesive isdisposed between the release liner and the film.

Films of the present invention may be prepared using any suitableprocess. By way of example, films of the present invention may beprepared using cast film processes, blown film processes, and extrusionand coextrusion processes.

Films of the present invention may be configured to provide suitablequalities for printing, such as receiving ink from a printer, includingink jet printers. In such embodiments, the ink absorption capacity andthe absorption speed of the film, and specifically the print layer of afilm, provide a suitable printing surface for good quality printing. Insuch embodiments, films of the present invention may dry suitably suchthat the ink does not remain wet for an undesirable period of time, andsuch films may also dry without significant cracking in the ink. Thefollowing examples provide additional details of exemplary embodimentsof films of the present invention.

In the following examples, films having a total thickness of 2.5 to 3.2mils were prepared. In addition, the films were tested using a corelayer comprised of 57% low density polyethylene (such as available fromFlint Hills Resources (“FHR”)) and 43% TiO₂ (such as available fromAmpacet Corporation) and an adhesive layer of 60% low densitypolyethylene, 30% Ampacet 111712, and 10% ethylene vinyl acetate. Forall examples, the gloss was measured using a BYK Gardner gloss meter,and the gloss reported is the average of the gloss measured in themachine direction (MD) and the cross direction (CD). The reference tablebelow provides an index to materials referenced in the followingexamples:

Material Description and Supplier PLEXIGLAS HFI-7 PMMA resin availablefrom Arkema Lotryl 29MA03 Random copolymer of ethylene and methylacrylate available from Arkema under the brand name Lotryl Lotader AX8900 Random terpolymer of ethylene, methyl acrylate, and glycidylmethacrylate available from Arkema under the brand name Lotader Lotader4700 Random terpolymer of ethylene, ethyl acrylate, and maleic anhydrideavailable from Arkema under the brand name Lotader Elvaloy 4924 Anethylene/vinyl acetate/carbon monoxide (E/VA/CO) copolymer availablefrom DuPont. Kraton FG1924G A linear triblock copolymer based on styreneand ethylene/butylene with a polystyrene content of 13% available fromKraton Polymers. Primacor 1321 An ethylene acrylic acid copolymeravailable from Dow Chemical. Kraton G 2832 Astyrene-ethylene/butylenes-styrene (SEBS) block copolymer available fromKraton Polymers. Denka TH-11 A styrene butadiene PMMA copolymeravailable from Denka Corporation. LA 2250 Methyl methacrylate-butylacrylate triblock copolymers available from Kuraray Co., Ltd. K resin KR53 Styrene-Butadiene Copolymer available from Cheveron Phillips ChemicalCompany LP. Styrenics 5410 High impact polystyrene available from IneosStyrenics LA 4285 (meth) acrylic thermoplastic elastomer from Kuraray CoLtd. Septon Q Thermoplastic elastomer from Kuraray Co Ltd. Levepren 400Ethylene vinyl acetate (40% VA content) from Lanxess KrystalgranPN03-221 Thermoplastic polyurethane from Huntsman Co. Denka TH-11Styrene-butadiene-PMMA available from Denka Corporation. Denka TX-100SStyrene-PMMA available from Denka Corporation. Nanostrength M51 PMMApolybutylacrylate-PMMA available from Arkema. Cadence GS2 PETGcopolyester available from Eastman Chemicals EA3400 General purposecrystal polystyrene available from Americas styrenics Ateva 1821 A EVAcopolymer with 18% VA content available from AT Plastics Inc. Zylar 960impact modified styrene acrylic copolymer available from Ineos styrenics

Example I

Multilayer films were produced using a conventional 4-layer cast filmco-extrusion process. Each of the four extruders A, B, C, D supplied amelt formulation to a feedblock where the melts were combined to form asingle molten stream consisting of four different layers. To achieve aprint layer thickness of about 0.6 to about 1.0 mils, both extruders Aand B were fed with the print layer formulation as indicated in thefollowing table. Extruders C was fed with molten layer of linear lowdensity polyethylene for forming the core layer of the film and linearlow density polyethylene and ethylene vinyl acetate for forming theadhesive layer were fed through extruder D. The extruder zonetemperatures were Z1=390° F., Z2=420° F., and Z3=420° F. and the dietemperature was 420° F. The extrudate from the die was cooled on a mattechill roll having a surface roughness average (Ra) of 40. The printlayer contacted the chill roll during the cooling process with a chillroll temperature set at 90° F. and an airknife speed of 60 Hz. Table Ishows the formulations used in the different extruders. In somevariations in Example I, no tie layer was included in the film.

The films were tested for printability using eco-sol and latex inkjetsystems. In the particular examples, printing of a multicolor test imagewas performed using a Roland Soljet Pro II XC-540 printer (availablefrom Roland Company) equipped with eco-sol Max inkjet inks, and an HPDesignjet L25500 printer (available from HP) equipped with HP 789 latexinks. In addition, print qualities were observed and recorded asreported in Table I below. As used below and in subsequent charts, “NM”designates that the value was not measured.

TABLE I Roland Soljet Unprinted Roland Soljet Pro II XC-540 HP PrinterPrint Layer Pro II XC-540 Printed Image (L25500) Print Layer Blend 60°Gloss Quality 60° Gloss Quality 100% PLEXIGLAS HFI-7 58 Cracks in imageNM Dry, image is good 83% PLEXIGLAS HFI-7 51 Dry to touch, no 55 NM 17%Lotryl 29MA03 cracks 75% PLEXIGLAS HFI-7 34 Dry to touch, no 49 NM 25%Lotryl 29MA03 cracks 75% PLEXIGLAS HFI-7 15 Dry to touch, no 39 NM 25%Lotader AX 8900 cracks 75% PLEXIGLAS HFI-7 19 Dry to touch, no 41 NM 25%Lotader 4700 cracks 40% PLEXIGLAS HFI-7 17 Dry to touch, no 62 Dry, nocracks, 40% Ethylene vinyl cracks, good image acetate (18% VA) 20%Ethylene vinyl acetate (26% VA) 75% PLEXIGLAS HFI-7 34 Dry to touch, no52 NM 25% Ethylene vinyl cracks acetate 70% PLEXIGLAS HFI-7 23 Dry totouch, no 45 NM 30% Elvaloy 4924 cracks 17% PLEXIGLAS HFI-7 19 Image iswet NM NM 83% Lotryl 29MA03 50% PLEXIGLAS HFI-7 12 Dry to touch, no 20NM 50% Lotader AX 8900 cracks 70% PLEXIGLAS HFI-7 32 Dry to touch, NM Nocracks 30% Kraton FG1924G cracks in image 70% PLEXIGLAS HFI-7 NM Dry totouch, 37 NM 30% Primacor 1321 coalescence 50% PLEXIGLAS HFI-7 Dry totouch, no 12 NM 50% Lotader 4700 cracks 30% PLEXIGLAS HFI-7 16 Dry totouch, no NM NM 70% Lotryl 29MA03 cracks 30% PLEXIGLAS HFI-7 20 Dry totouch, no 55 Image is good, no 20% Ethylene vinyl cracks cracks acetate(26% VA) 30% Ethylene vinyl acetate (18% VA) 20% Kraton G 2832 30%PLEXIGLAS HFI-7 17 Dry to touch, no 61 Image is good, no 30% Ethylenevinyl cracks cracks acetate (26%) 40% Ethylene vinyl acetate (18%) 80%PLEXIGLAS HFI-7 76 Dry to touch, NM Image is good, no 20% Denka TH-11Cracks cracks (Styrene butadiene PMMA copolymer) 50% Plexiglas HFI-7 NMDry, image is NM Good image 50% LA 2250 slightly washed (poor colordensity) 50% Plexiglas HFI-7 NM Good image NM Good image 25% LA 2250 25%Lotryl 29MA03 50% Styrenics 5410 NM Good image NM Good image 50% KratonG 2832 50% LA 4285 NM Good image NM Good image 50% Lotryl 29MA03 50%Plexiglas HFI-7 NM Good image NM Good image 50% Septon Q 50% PlexiglasHFI-7 NM Good image NM Good image 50% Levepren 400 100% EA3400 NM Verylight color NM Good image density; film surface dissolved by the inkdrops locally and, as result, it lots of tiny dents formed on thesurface 100% Ateva 1812A NM print is very wet, NM Good image severe inkbleeding 70% Styrenic 5410 + 30% NM Dry to touch, NM NM Kraton G2832good image 30% EA3400 + 70% NM Dry to touch, NM Good image Ateva 1821Agood image 50% EA3400 + 50% NM Dry to touch, NM Good image Ateva 1821Agood image 60% EA3400 + 40% NM Dry to touch, NM Good image Ateva 1821Agood image 60% EA3400 + 30% NM Dry to touch, NM Good image Ateva 1821A +10% good image Kraton G2832 70% EA3400 + 30% NM Dry to touch, NM Goodimage Ateva 1821A good image 50% Zylar 960 + 50% NM Dry to touch, NMGood image Ateva 1821A good image 50% Cadence GS2 NM Dry to touch, NMGood image 50% Lortyl 29MA03 good image

Thus, it was observed that a suitable blend of high absorption materialand low absorption material in a print layer resulted in suitable andimproved print quality. Although ink cracking had been observed in filmshaving over 83% PMMA without olefin copolymer in the print layer, suchcracking was not shown for blends with 83% or less PMMA when blendedwith at least 10% by weight of olefin copolymer. In the Eco-sol inkjetprinting, crystal polystyrene, impact modified styrene, and acrylicstyrene copolymer themselves have high ink absorption and may bepartially dissolved by an ink solvent at high ink loading, which mayresult in light color density and appearance of micro ink drop dents ona surface after printing. However, after blending such materials in theprint layer with low ink absorption material(s) such as EVA or SEBS, itwas observed in testing that the print quality was improved.

In addition, as shown in FIGS. 4A-4B, scanning electron microscopeimages were obtained for some of the examples in Table I. In particular,FIG. 4A is a scanning electronic microscope image of the film having aprint layer of 83% Arkeman HIF-7 and 17% Lotryl 29MA03 and FIG. 4B is animage of a film having a print layer of 30% Arkema HFI-7 and 70% Lotryl29MA03. As shown in those figures, the blend forming the print layershows discrete domains, which indicates an incompatible blend. Thisincompatable blend is further confirmed by the DMA profile, which isshown in FIG. 4C. This profile depicts distinct glass transitiontemperatures (Tg) for the separate components of the blend. Furthermore,as shown in the profile, a comparison shows that the modulus of theblend lies between the modulus of each of the two components used toform the blend.

Example II

A multilayer film was prepared similar to Example I except the printlayer included two layers comprised a blend of Plexiglas HFI-7 withdifferent polymers at different ratios in the adjacent layers such thatthe absorption capacities of the two adjacent layers were different. Thetwo adjacent layers collectively form the print layer of the film, andthe print layer (including all layers in the print layer) was about 0.6to about 1 mil thick. Table II shows the formulations used in the twoadjacent layers. The core layer and the adhesive layers were the same asin Example I. The films of this example were then tested in the samemanner described above for Example I, and the results are recorded belowin Table II.

TABLE II Roland Soljet Pro II XC-540 Roland Soljet HP Printer PrintedImage Pro II XC-540 (L25500) Print Layer I Print layer II 60° GlossQuality Quality 100% Lotryl 29MA03 30% PLEXIGLAS HFI-7 NM Image is Imagegood 70% Lotryl 29MA03 wet 100% PLEXIGLAS HFI-7 100% Lotryl29MA03 NMImage is NM dry, cracks 70% PLEXIGLAS VM-100 50% PLEXIGLAS VM-100 35 Dryto Dry, image 30% Lotader 4700 50% Lotader 4700 touch, no good cracks60% PLEXIGLAS VM-100 50% PLEXIGLAS VM-100 17 Dry to Dry, image 40%Lotader 4700 50% Lotader 4700 touch, no good cracks 70% PLEXIGLAS HFI-750% PLEXIGLAS HFI-7 37 Dry, Dry, no 30% Primacor 1321 50% Primacor 1321coalesce, cracks, ink bleed image good 50% PLEXIGLAS HFI-7 30% PLEXIGLASHFI-7 NM Dry to Dry to 50% Lotader 4700 70% Lotader 4700 touch, touch,good image good image 40% PLEXIGLAS HFI-7 50% PLEXIGLAS HFI-7 23 Dry toDry to 60% Lotader AX 8900 50% Lotader AX 8900 touch, touch, image goodimage good 30% PLEXIGLAS HFI 10-101 70% PLEXIGLAS HFI 10-101 32 Dry toDry to 70% Lotader AX8900 30% Lotader AX 8900 touch, touch, image goodimage good 50% Krystalgran PN03-221 60% PLEXIGLAS HFI-7 18 Dry to Dry to50% PLEXIGLAS HFI-7 40% Lotader 4603 touch, no touch, cracks image good70% Krystalgran PN03-221 60% PLEXIGLAS HFI-7 14 Dry to Dry to 30%PLEXIGLAS HFI-7 40% Lotader 4603 touch, touch, cracks image good 30%Krystalgran PN03-221 60% PLEXIGLAS HFI-7 18 Dry to Dry to 70% PLEXIGLASHFI-7 40% Lotader 4603 touch, no touch, cracks image good 50% PLEXIGLASHFI-7 30% PLEXIGLAS HFI-7 13 NM Print is dry, 50% LA2250 70% Lotryl29MA03 cracks in image 50% PLEXIGLAS HFI-7 50% PLEXIGLAS HFI-7 10 Printis dry, Print is dry, 50% Krystalgran PN03-221 50% Krystalgran PN03-221no cracks no cracks

By using different blend ratios in adjacent layers to form the printlayer, a morphological gradient is created in the print layer resultingin a print layer with varying absorption capacities across the printlayer thickness.

Example III

Multilayer films similar to Example I were created by co-extruding thelayers as described in Example I but using a PMMA copolymer. The corelayer and the adhesive layers were the same as in Example I. Thecopolymers of PMMA used in the blends are provided in Table III below.Films indicated with an asterisk (*) were nipped to a matte roll duringthe extrusion process. The films of this example were then tested in thesame manner described above for Example I, and the results are recordedbelow in Table III.

TABLE III Roland XC-540 HP Designjet Unprinted Soljet Pro II Eco-solL25500, HP Printed Film 60° Eco-sol max Printed Image HP 789 latex Image60° Print Layer Formulation Gloss Quality 60° Gloss ink Quality Gloss100% Denka TH-11 48 Cracks, Washed NM Image is good, 53 out image(poorno cracks color density) 50% Denka TH-11   15 * Dry/no cracks 46 NM NM50% Lotryl 29MA03 40% Denka TH-11   18 * Dry/no cracks 49 Image is good,20 60% Lotryl 29MA03 dry no cracks 50% Plexiglas HFI-7 10 Dry to touch,NM NM NM 50% LA 2250 cracks in image 30% Plexiglas HFI-7 13 Print is wetNM NM NM 70% LA2250 20% Denka TX-100S 76 Dry to touch/ NM Image is good,52 80% Plexiglas HFI-7 cracks no cracks 50% Plexiglas HFI-7 66 Dry totouch, NM NM NM 50% Denka TH-11 cracks in image 40% SAN 91 Severecracks, NM No cracks, dry NM 60% Plexiglas HFI-7 image washed to touch,image out (poor color washed out (poor density) color density)

As shown in Table III, the addition of ethylene acrylic copolymercontent in the blend of PMMA or copolymer of PMMA eliminates the cracksthat are observed in the image when printed with eco-sol ink.

Example IV

Example V was a multilayer film produced similar to the Example I exceptthat the print layer included a blend of PMMA and an ethylene-basedcopolymer and a block copolymer to improve the phase compatibility and,consequently, the gloss of the print surface. The components for theprint layer were first compounded using a twin screw extruder equippedwith a pelletizer. The compounded pellets were then fed into the singlescrew extruder as described in Example I. Printability was tested withRoland eco-sol system described above, which had been established inprevious testing as the most difficult solvent to print, and HP PatexL25500 printers. The copolymers and layers are listed in Table IV. Thesurface gloss of the films were measured using Gardner Glossmeter andare reported below, wherein the data represents the average of the glossmeasured in MD and CD. The following materials are also reference inthis example:

Trade Name Copolymer Manufacturer Xiran SE 700 Styrene maleic anhydridePolyscope (15% maleic anhydride) Xiran SZ23110 Styrene maleic anhydridePolyscope (23% maleic anhydride) Xiran SZ1570 Styrene maleic anhydridePolyscope (15% maleic anhydride) Kraton G 1726 Styrene-butylene(diblock) Kraton Polymers Kraton G 1657 Styrene-butylene-Styrene(triblock) Kraton Polymers Blendex 6201 Styrene acrylonitrile/MaleicGalata Chemicals anhydride Royaltuf 50% Styrene acrylonitrile/50%Chemtura 373P20 Ethylene propylene diene monomer Corporation (EPDM)Nanostrength PMMA-Poly(butyl acrylate)-PMMA Arkema MAM-M52 (triblock)Elvaloy 4926 Ethylene vinylacetate carbon Dupont monoxide

TABLE IV Eco-Sol Unprinted Printed HP Printed Film 60° Image Image BlendFormulation Gloss % Eco-sol 60° Gloss HP Latex 60° Gloss 30% PLEXIGLASHFI-7 17 Dry, 40 Image is 27 50% Lotryl 29MA03 image good, no 20% KratonG 1726 good cracks 25% PLEXIGLAS HFI-7 16 Dry, 36 NM NM 55% Lotryl29MA03 image 10% Kraton G 1657 good 10% Xiran SZ15170 25% PLEXIGLASHFI-7 13 Dry, 40 NM NM 65% Lotryl 29MA03 image 10% Xiran SE 700 good 30%PLEXIGLAS HFI-7 16 Dry, 42 Image is 32 60% Lotryl 29MA03 image good, no10% Blendex 6201 good cracks 30% PLEXIGLAS HFI-7 6 Dry, 20 Image is 1560% Lotryl 29MA03 image good, no 10% Royaltuf 373P20 good cracks 30%PLEXIGLAS HFI-7 16 Dry, NM Image is 28 50% Lotryl 29MA03 image good, no10% Xiran SZ 15170 good cracks 10% Kraton G 1726 30% PLEXIGLAS HFI-7 16Dry, 39 NM NM 60% Lotryl 29MA03 image 10% Denka TH-11 good 30% PLEXIGLASHFI-7 10 Dry, 30 Image is 20 60% Lotryl 29MA03 image good, no 10% XiranSZ23110 good cracks 30% PLEXIGLAS HFI-7 12 Dry, 34 NM NM 60% Lotryl29MA03 image 10% Xiran SZ15170 good 53% PLEXIGLAS HFI-7 17 Dry, 40 NM NM37% Lotryl 29MA03 image 10% Kraton G 2832 good 65% PLEXIGLAS HFI-7 21Dry, 44 NM NM 25% Lotryl 29MA03 image 10% Elvaloy 4926 good 30%PLEXIGLAS HFI-7 16 Dry, 42 Image is 39 50% Etylene Vinyl acetate imagegood, dry, no 10% Xiran SZ15170 good cracks 10% Kraton G 1726

Example V

Example V was a multilayer film formed similar to Example III above butusing PMMA from three different sources. With reference to Table Vbelow, the Parapet TNA was sourced from Kuraray America and thenanostrength polymers were obtained from Arkema. The print layerformulation was pre-compounded using a twin screw extruder as describedin Example IV. The preformed pellet was fed into a screw extruder andco-extruded into a multilayer film. The resulting multilayer films wereevaluated using the same Roland eco solvent printer discussed above anda Mimaki JV33 (mild solvent) inkjet printer available form Mimaki, USA.

TABLE V Roland Eco-sol Mimaki Mild Blend Printer solvent PrinterFormulation Core Layer Adhesive Layer 60° (Comments/ (Comments/ (Printlayer) Formulation Formulation Gloss 60° Gloss) 60° Gloss) 30% ParapetTNA 57% FHR LDPE 60% LDPE 9 Dry to touch, Dry to touch, 60% Lotryl 43%Ampacet 30% Ampacet good image good image 29MA03 TiO2 111712 40 26 10%Kraton G 10% EVA 1657 40% Parapet TNA 57% FHR LDPE 60% LDPE 9 Dry totouch, Dry to touch, 52% Lotryl 43% Ampacet 30% Ampacet good image goodimage 29MA03 TiO2 111712 38 24 8% Kraton G 10% EVA 1657 40% Parapet TNA57% FHR LDPE 60% LDPE 8 Dry to touch, Dry to touch, 52% Lotryl 43%Ampacet 30% Ampacet poor color poor color 29MA03 TiO2 111712 densitydensity 8% Xiran SE700 10% EVA 17 17 40% Plexiglas 57% FHR LDPE 60% LDPE25 Dry to touch, Dry to touch, HFI-7 43% Ampacet 30% Ampacet good imagegood image 52% Lotryl TiO2 111712 47 48 29MA03 10% EVA 8% Kraton G 165750% 57% FHR LDPE 60% LDPE 28 Dry to touch, Dry to touch, NanostrengthE21 43% Ampacet 30% Ampacet very good image very good 50% Lotryl TiO2111712 49 image 29MA03 10% EVA 57 50% 57% FHR LDPE 60% LDPE 17 Dry totouch Dry to touch Nanostrength 43% Ampacet 30% Ampacet 25 30 MAM-M52TiO2 111712 50% Lotryl 10% EVA 29MA03 100% 57% FHR LDPE 60% LDPE N/ADry, washed out N/A Nanostregth 43% Ampacet 30% Ampacet image (poorMAM-M52 TiO2 111712 color density) 10% EVA

As demonstrated by the results above, the addition of block copolymer tothe blend as a compatibilizer may improve the print quality of the imageas well as the structural compatibility with ethylene methacrylate. Insome embodiments, it was also observed that Nanostrength E21, which haspolybutadiene midblock, shows better gloss and print characteristicsthan Nanostrength M52, which has poly(butyl acrylate) midblock.

Example VI

In this example, multilayer films were formed similar to Example III.The print layer formulation was pre-compounded into a pellet beforebeing fed into a single screw extruder. In addition, extrudate from thedie was cooled onto a chrome roll and nipped with a rubber roll toimprove the surface gloss of the incompatible blend layer. Theformulations are listed in Table VI below.

The films were tested for printability and gloss by printing the imageusing a variety of inkjet systems. The gloss of the film was testedbefore and after printing the image. In addition to thepreviously-described printers, a Mimaki UJF 3042 (UV inkjet) printeravailable from Mimaki USA was also used in this testing. The testingresults are provided in Table VI below.

TABLE VI Roland HP Mimaki Mimaki XC-540 L25550 UJF 3042 JV33 (Eco-sol)(Latex (UV ink) (Mild Inkjet ink) Inkjet solvent) Print Layer UnprintedPrinter Inkjet Printer Inkjet Print Layer Thickness Film 60° 60° 60° 60°Printer Sample Formulation (mils) Gloss Gloss Gloss Gloss 60° Gloss 160% Lotryl 1.2 52 55 59 20 73 29MA03 40% Denka TH- 11 2 30% Plexiglas1.25 60 64 67 20 74 HFI-7 60% Lotryl 29MA03 10% Kraton G 1657 3 30%Plexiglas 1.08 63 56 54 21 69 HFI-7 60% Lotryl 29MA03 10% Denka TH- 11 425% Plexiglas 1.5 62 61 60 NM 74 HFI-7 50% Lotryl 29MA03 15% Denka TH-11 10% Kraton G 1726 5 30% Plexiglas 1.23 54 62 51 NM 71 HFI-7 60%Lotryl 29MA03 10% Polyscope SE700 6 25% Plexiglas 1.40 59 58 59 NM 71HFI-7 50% Lotryl 29MA03 15% Polyscope SE 700 10% Kraton G 1726

From the results above, it was observed that the use of a chrome castingroll resulted in improved gloss of the film. For reference, it wasobserved that the gloss of the films tested above were generallycomparable to the gloss of the TrueImpact (“TMP”) 7000 series productsold commercially by Avery Dennison Corporation, which is a gloss in therange of about 50 to about 70.

Scanning electron microscope images were also obtained for some of thefilms in Table IV. For example, FIG. 5 is a scanning electron microscopecross-section image of a print layer formulation having 30% PlexiglasHFI-7, 60% Lotryl 29MA03, and 10% Kraton G1657 (Sample 2 in Table VI).It was observed in this image that the copolymer formulation in theprint layer reduced the size of the domains of the incompatible blend.

In addition, the films from Table VI were tested for printability oneach printer described in Table Vi. Upon review, the print image fromeach printer was of good and suitable quality. In addition, no imageshowed any print defects.

The print images obtained from the Roland XC-540 (eco-sol) printer, HPL25500 (latex) printer, and Mimaki JV33 (mild solvent) printers werefurther analyzed using a QEA PIAS-II meter to determine the dot size andink bleeding characteristics of the print quality obtained from themultilayer films of the present invention against TrueImpact (“TMP”)7000 (sustainable print media sold by Avery Dennison Corporation) andthe standard vinyl products under the trade name MP12105 and MPI 2900also sold by Avery Dennison Corporation. The following results wererecorded:

TABLE VII Dot Size Results Roland XC-540 HP L25500 Mimaki Mild Eco-solMean Latex Mean Solvent Mean Dot Size Dot Size Dot Size Print Media(Micron) (Micron) (Micron) TrueImpact 39.5 41.7 N/A (TMP 7000) MPI210540.4 48 N/A MPI2900 54.2 45 45.5 Sample 1 47.5 N/A 34.3 Sample 2 46.8N/A 38.6 Sample 3 44.4 39.3 35.5 Sample 4 47.1 38.9 36.4 Sample 5 42.7N/A 34.5 Sample 6 47.9 N/A 35.5

TABLE VIII Color Bleeding Measurements Roland XC- Roland XC- 540 540 HPL2550 HP L2550 Mimaki Mimaki Width of Width of Width of Width of Widthof Width of black line in magenta black line in magenta black line inmagenta magenta line in black magenta line in black magenta line inblack area area area area area area Print Media (micron) (micron)(micron) (micron) (micron) (micron) TrueImpact 1113.0 859.0 1085.0 869.0N/A N/A (TMP 7000) MPI2105 1120.7 871.7 1079.3 894.7 N/A N/A MPI 29501097.7 904.1 1106.0 898.7 1458.6 1143.9 Sample 1 1113.4 888.3 N/A N/A1499.3 1148.3 Sample 2 N/A N/A N/A N/A N/A N/A Sample 3 1094.1 869.91108.6 872.2 1529.1 1108.7 Sample 4 1141.9 841.9 1141.1 832.3 1567.41070.2 Sample 5 1118.0 864.7 N/A N/A 1436.3 1094.5 Sample 6 1149.8 826.1N/A N/A 1544.6 1065.3

As shown above, both the dot sizes and the bleed characteristics of themultilayer films of the present invention are similar in quality toknown vinyl products in the market. In addition, the print qualitybetween the multilayer films of the present invention are similar to theaccepted print quality of the known vinyl media.

Example VII

In this example, a TrueImpact overlaminate film sold by AveryDennisonCorporation as TOL 7000 series was laminated with the 58072 adhesive,available from Avery Dennison, to the print surface of some of thesamples of Example VI. The 60-degree gloss of the TOL 7000 series wasmeasured to be between 80-90. As provided in the results below, it wasobserved that the gloss of the film with the laminate may besignificantly increased with a laminate relative to the original film.

Unprinted Gloss of Sample ID film gloss laminated film Sample 2 67 84Sample 5 61 85 Sample 6 65 85

Example VIII

Multilayer films were formed similar to Example III. The print layerformulation of 60% Lotryl 29MA03 and 40% Plexiglas HFI-7 waspre-compounded using a twin screw extruder into a pellet before beingfed into a single screw extruder. The extruder RPM values were changedto create three different samples with different print layerthicknesses. The formulations, thicknesses (determined from scanningelectron microscope measurements), and results were as follows:

Print Layer Formulation Thickness Eco-sol Printing Comments 40%Plexiglas HFI-7  1.2 mils Dry to touch, good image 60% Lotryl 29MA03 40%Plexiglas HFI-7 0.73 mils Dry to touch, good image 60% Lotryl 29MA03 40%Plexiglas HFI-7 0.38 mils Wet in the dark colors 60% Lotryl 29MA03

These results suggest that a minimum thickness of the print layer shouldbe greater than 0.38 mils to achieve drying of the image.

Embodiments of the present invention may be used for any suitablepurpose. In some embodiments, films of the present invention may beprinted to create signs, posters, banners, and other printed materials.Films of the present invention may be printed upon using a selection ofone or more inks from a variety of inks. In specific embodiments, filmsof the present invention may be suitable for inkjet printing. Generallyin inkjet printing, ink is deposited onto the film surface as dots,which then spread and join together to provide, ideally, a substantiallyuniform appearance. As demonstrated by the examples above, films of thepresent invention do not, in some embodiments, require a specific typeof ink but may be suitably printed with one or more of a variety ofsuitable inks for inkjet printing.

These and other modifications and variations to the present inventionmay be practiced by those of ordinary skill in the art without departingfrom the spirit and scope of the present invention, which is moreparticularly set forth in the appended claims. In addition, it should beunderstood that aspects of the various embodiments may be interchangedin whole or in part. Furthermore, those of ordinary skill in the artwill appreciate that the foregoing description is by way of exampleonly, and it is not intended to limit the invention as further describedin such appended claims. Therefore, the spirit and scope of the appendedclaims should not be limited to the exemplary description of theversions contained herein.

What is claimed is:
 1. A printing layer comprising a plurality ofsublayers; wherein each sublayer independently comprises a blend of atleast one high absorption capacity material selected from the groupconsisting of poly(methyl methacrylate), modified poly(methylmethacrylate), impact modified polystyrene, styrene acrylic copolymer,styrene-olefin copolymer, styrene-acrylic-olefin copolymer,acrylonitrile butadinene styrene polymer, styrene acrylonitrile polymer,copolyester polymer; and at least one low absorption capacity material;wherein the at least one low absorption material comprises an olefinpolymer; and wherein an absorption capacity gradient is present betweenat least two adjacent sublayers within the printing layer.
 2. Theprinting layer of claim 1 wherein the olefin polymer is one or more ofethylene acrylate copolymers, ethylene vinyl acetate, ethylene acrylicester terpolymer, and styrene-ethylene/butylenes-styrene (SEBS) blockcopolymer.
 3. The printing layer of claim 1 wherein the olefin polymeris selected from the group consisting of random copolymers and blockcopolymers.
 4. The printing layer of claim 1 wherein the printing layerconsists of two sublayers.
 5. The printing layer of claim 1 wherein theprinting layer comprises a first sublayer and a second sublayer; whereinthe second sublayer comprises absorbing particles.
 6. The printing layerof claim 1 wherein at least one sublayer of the printing layer comprisespoly(methyl methacrylate) as the high absorption capacity material; andwherein the poly(methyl methacrylate) is present in an amount of fromabout 20% to about 83% by weight of the at least one sublayer.
 7. Theprinting layer of claim 1 further comprising a compatibilizer.
 8. Theprinting layer of claim 1 further comprising free radical scavengers andan ultraviolet light stabilizer.
 9. A film for printing comprising aprinting layer, a core layer, and an adhesive layer, wherein the corelayer is between the printing layer and the adhesive layer, and whereinthe printing layer comprises a plurality of sublayers; wherein eachsublayer independently comprises a blend of at least one high absorptioncapacity material selected from the group consisting of poly(methylmethacrylate) and modified poly(methyl methacrylate); and at least onelow absorption capacity material; wherein the at least one lowabsorption material comprises one or more polyolefin polymers; andwherein an absorption capacity gradient is present between at least twoadjacent sublayers within the printing layer.
 10. The film of claim 9further comprising a tie layer located between the printing layer andthe core layer.
 11. The film of claim 9 wherein the core layer furthercomprises color pigments.
 12. The film of claim 9 wherein the adhesivelayer comprises ethylene vinyl acetate.
 13. The film of claim 9 furthercomprising an overlaminate adhered to the printing layer.
 14. Theprinting layer of claim 1 wherein the printing layer has a thicknessgreater than 0.38 mils.
 15. The printing layer of claim 1 wherein atleast one of the sublayers comprises at least about 20% by weight ofhigh absorption capacity material, and at least about 10% by weight oflow absorption capacity material.
 16. The film of claim 9 wherein theprinting layer comprises a first sublayer and a second sublayer; whereinthe second sublayer comprises absorbing particles.
 17. The film of claim9 wherein at least one sublayer of the print layer comprises poly(methylmethacrylate) as at least 50% by weight of the layer and wherein atleast one sublayer of the printing layer comprises less than 50% byweight of poly(methyl methacrylate).
 18. The film of claim 9 furthercomprising free radical scavengers and an ultraviolet light stabilizer.19. The film of claim 18 wherein the free radical scavengers comprisehindered amine light stabilizer (HALS) in an amount of about 0.05 toabout 2 percent by weight.
 20. The film of claim 18 wherein theultraviolet light stabilizers comprise benzophenone in amounts rangingfrom about 0.1 to about 5 percent by weight.
 21. The printing layer ofclaim 1 wherein the printing layer further comprises one or morepigments, antiblock agents, and/or matting agents.
 22. The film of claim20 wherein the film further comprises a removable release liner and apressure sensitive adhesive, wherein the pressure sensitive adhesive isdisposed upon the adhesive layer and the release liner is adjacent tothe pressure sensitive adhesive, such that the pressure sensitiveadhesive is disposed between the adhesive layer and the release liner.23. The printing layer of claim 2, wherein the ethylene acrylatecopolymers are selected from the group consisting of ethylene acrylicacid, ethylene methyl acrylate, and ethylene butyl acrylate.
 24. Theprinting layer of claim 1, wherein the at least one high absorptioncapacity material comprises the styrene-acrylic-olefin copolymer. 25.The printing layer of claim 1, wherein the olefin polymer comprisesethylene butyl acrylate.
 26. The printing layer of claim 1, wherein theolefin polymer comprises an ethylene acrylic ester terpolymer.
 27. Theprinting layer of claim 1, wherein the at least one high absorptioncapacity material comprises poly(methyl methacrylate); and wherein theat least one low absorption capacity material comprises anethylene-acrylic copolymer.
 28. The film of claim 9, wherein the atleast one high absorption capacity material comprises poly(methylmethacrylate); and wherein the at least one low absorption capacitymaterial comprises an ethylene-acrylic copolymer.
 29. The printing layerof claim 1, wherein some but not all of the sublayers comprise freeradical scavengers and an ultraviolet light stabilizer.
 30. The film ofclaim 9, wherein some but not all of the sublayers comprise free radicalscavengers and an ultraviolet light stabilizer.
 31. The printing layerof claim 1 wherein at least one of the sublayers comprises at least 17%by weight of the at least one low absorption capacity materials and atmost 83% by weight of the least one high absorption capacity material.